Simplify the following expression: $y = \dfrac{10n^2 - 20n - 800}{n + 8} $
Explanation: First factor the polynomial in the numerator. We notice that all the terms in the numerator have a common factor of $10$ , so we can rewrite the expression: $ y =\dfrac{10(n^2 - 2n - 80)}{n + 8} $ Then we factor the remaining polynomial: $n^2 {-2}n {-80} $ ${8} {-10} = {-2}$ ${8} \times {-10} = {-80}$ $ (n + {8}) (n {-10}) $ This gives us a factored expression: $\dfrac{10(n + {8}) (n {-10})}{n + 8}$ We can divide the numerator and denominator by $(n - 8)$ on condition that $n \neq -8$ Therefore $y = 10(n - 10); n \neq -8$